As his place will probably be filled by a dvd/sacd player in the very near future, i am thinking about modding my cd-850mkII - it would be a shame to do nothing with this player.
(I will certainly try the dddac1543 - waiting for the parts to arrive...).
This is supposed to be a rather good player from Philips (it is pretty old now, but still works just fine - also the sound is not bad at all), yet there is very little to be found about this player on the internet(?).
Anybody out there who can give me directions to schematics improvements/ modifications?
(I will certainly try the dddac1543 - waiting for the parts to arrive...).
This is supposed to be a rather good player from Philips (it is pretty old now, but still works just fine - also the sound is not bad at all), yet there is very little to be found about this player on the internet(?).
Anybody out there who can give me directions to schematics improvements/ modifications?
schematics great!
Roberto,
Thanks for the offer - would be a great help!
However do not see your e-mail address. Can you mail me ? (link on bottom of this message)
Just opened the player and indeed there are separated boards. I guess I can take I2s from saa7210.
Btw do you know if marantz cd62= philips 850mkII ? I saw a picture of the marantz on this forum and the inside looks identical.
I would really appreciate the schematics,
thanks!
Roberto,
Thanks for the offer - would be a great help!
However do not see your e-mail address. Can you mail me ? (link on bottom of this message)
Just opened the player and indeed there are separated boards. I guess I can take I2s from saa7210.
Btw do you know if marantz cd62= philips 850mkII ? I saw a picture of the marantz on this forum and the inside looks identical.
I would really appreciate the schematics,
thanks!
Peng,
I can't tell on CD62. I have seen some Philips-Marantz players that have a similar decoder board with different DAC and other complementary boards (FTS, headphones, etc).
When you see the schematics of CD-850 it will become clear the connection of the boards (the biggest connector carries the I2S data).
Sorry for the missing email link, I think I have corrected that.
Roberto
I can't tell on CD62. I have seen some Philips-Marantz players that have a similar decoder board with different DAC and other complementary boards (FTS, headphones, etc).
When you see the schematics of CD-850 it will become clear the connection of the boards (the biggest connector carries the I2S data).
Sorry for the missing email link, I think I have corrected that.
Roberto
CD850 MkII ckt diagram.
Hi Roberto,
I tried to email you privately but I am not sure if it will get to you.
I would also like to have the circuit diagram of the CD850 MkII. I also have a machine which I want to modify.
You can email me at amadhavan(at)eth.net
Please change the (at) for @.
Thanks in advance.
Wish you all a Very Happy New Year .
Ashok.
Hi Roberto,
I tried to email you privately but I am not sure if it will get to you.
I would also like to have the circuit diagram of the CD850 MkII. I also have a machine which I want to modify.
You can email me at amadhavan(at)eth.net
Please change the (at) for @.
Thanks in advance.
Wish you all a Very Happy New Year .
Ashok.
Your mail.
Hi Roberto,
Thanks for all your effort. I did not get your mail but I also found out that my "eth.net" mailbox accepts only some types of files ( no pdf !).
Better you send it to
ashokm@sathyam.net.in and you could copy it to ashokm@sify.com .
One of these should accept the file.
Thanks again,
Ashok.
Hi Roberto,
Thanks for all your effort. I did not get your mail but I also found out that my "eth.net" mailbox accepts only some types of files ( no pdf !).
Better you send it to
ashokm@sathyam.net.in and you could copy it to ashokm@sify.com .
One of these should accept the file.
Thanks again,
Ashok.
Look before you leap
Hi Peng
I have a Philips CD624 which is of similar age to your 850Mk11 and uses similar technology to the 850Mk1. Unfortunately, it is not built quite as well as your machine. I was planning on doing something like you are doing, ie replace the DAC with something a bit more interesting. However, I am now having second thoughts as reliable sources have informed me that these earlier Bitstream DAC's can be surprisingly good if some carefull mods are done to the player.
I know of one serious DIYer who has modded a CD634 by replacing the clock with a TENT clock and improved the output opamps. The sound of this machine compares favourably with his TDA1541A equipped machine. He has described the SAA7321 DAC (which should be similar to yours), as the best sounding 1 Bit DAC ever.
I hope I don't start a Multibit/nos vs Single bit war here, but maybe you should consider some other mods first before leaping in to change what could be a very good version of one technology, for an economy version of another technology.
Unfortunately, I can't give you a first hand opinion of which approach I would prefer as I have not made a direct comparison. I am just giving you my thoughts on how I will approach my project.
Good luck
Fin
Hi Peng
I have a Philips CD624 which is of similar age to your 850Mk11 and uses similar technology to the 850Mk1. Unfortunately, it is not built quite as well as your machine. I was planning on doing something like you are doing, ie replace the DAC with something a bit more interesting. However, I am now having second thoughts as reliable sources have informed me that these earlier Bitstream DAC's can be surprisingly good if some carefull mods are done to the player.
I know of one serious DIYer who has modded a CD634 by replacing the clock with a TENT clock and improved the output opamps. The sound of this machine compares favourably with his TDA1541A equipped machine. He has described the SAA7321 DAC (which should be similar to yours), as the best sounding 1 Bit DAC ever.
I hope I don't start a Multibit/nos vs Single bit war here, but maybe you should consider some other mods first before leaping in to change what could be a very good version of one technology, for an economy version of another technology.
Unfortunately, I can't give you a first hand opinion of which approach I would prefer as I have not made a direct comparison. I am just giving you my thoughts on how I will approach my project.
Good luck
Fin
sure will
Hi Fin,
Thanks for your thoughts. I will receive a Tent clock in the next couple of weeks and would be interested to try it out, and compare the present DAC with the dddac1543.
My player uses saa7322(as filter?)/saa7350(as DAC).
No destructive changes will be made (at least not before comparing both topologies).
Roberto(RR- who was also so kind to send me the schematics) has put in a tent clock fed by battey with a charger relay. I'm interested to see how he implemented this in the 850.
The opamps in the 850mkII are LM833's. Do you know what would be be a good replacement with proven (better) result ?
greetz,
Peter
Hi Fin,
Thanks for your thoughts. I will receive a Tent clock in the next couple of weeks and would be interested to try it out, and compare the present DAC with the dddac1543.
My player uses saa7322(as filter?)/saa7350(as DAC).
No destructive changes will be made (at least not before comparing both topologies).
Roberto(RR- who was also so kind to send me the schematics) has put in a tent clock fed by battey with a charger relay. I'm interested to see how he implemented this in the 850.
The opamps in the 850mkII are LM833's. Do you know what would be be a good replacement with proven (better) result ?
greetz,
Peter
Peng said:
Hello Peter,
I've found an ASCII esch. from an old email (weird). I hope it's clear enough.
The circuit needs connections to a +15v supply, chosen because there are one line spare from the original op-amps, now unused.
The kill signal (~3v) connects the charger to the battery when no music sounds through relay 1. Relay 2 disconnects the battery from the XO on power down.
The 7805 regulator is configured as a current source, that brings (5v+2.7v)/499R = 15mA. Given that the XO uses 10mA, you end with a charge of 5mA, that should be safe for the battery and keep it charged with normal use of the player.
Now I would delete the zener, and change charge resistor accordingly (I blindly copied an elektor sch. then), and maybe increase the charge current. If someone could suggest ideal values it would be great.
Cheers,
Roberto
Attachments
Hi Peng
For opamps I have planned to audition the usual suspects ie. AD8065, AD8066, AD825, AD826, OPA627, OPA637, OPA2134, LM6172. I havn't got arround to it yet so no first hand info - sorry. However, I can send you an article describing the sound and application of some of these opamps.
Lately I have started thinking about using a different analogue stage and bypassing the onboard opamps/filtering of the DAC, the output opamps and muting circuit. Have a look at this.....
http://www.fortunecity.com/rivendel...fda/vasfda.html
Good luck
Fin
For opamps I have planned to audition the usual suspects ie. AD8065, AD8066, AD825, AD826, OPA627, OPA637, OPA2134, LM6172. I havn't got arround to it yet so no first hand info - sorry. However, I can send you an article describing the sound and application of some of these opamps.
Lately I have started thinking about using a different analogue stage and bypassing the onboard opamps/filtering of the DAC, the output opamps and muting circuit. Have a look at this.....
http://www.fortunecity.com/rivendel...fda/vasfda.html
Good luck
Fin
Sorry about the above link. This one should work.
http://www.fortunecity.com/rivendell/xentar/1179/theory/vasfda/vasfda.html
http://www.fortunecity.com/rivendell/xentar/1179/theory/vasfda/vasfda.html
Thanks.
Hi Roberto ,
Thanks for your effort.
I think that the switched capacitor filter in the SAA7350 will be looked down upon by most guys. But apart from making drasatic mods we could probably take the outputs from there ( 7350) and implement passive filters and a tube stage in an effort to improve the sound. I will work on this and hope we can come up with something far better.
The mute transistors will have to go and we could use a small dip relay instead.
Right now I have used the OPA2134 which is better than the LM833 . It is better, but not good enough.
Cheers,
Ashok.
Hi Roberto ,
Thanks for your effort.
I think that the switched capacitor filter in the SAA7350 will be looked down upon by most guys. But apart from making drasatic mods we could probably take the outputs from there ( 7350) and implement passive filters and a tube stage in an effort to improve the sound. I will work on this and hope we can come up with something far better.
The mute transistors will have to go and we could use a small dip relay instead.
Right now I have used the OPA2134 which is better than the LM833 . It is better, but not good enough.
Cheers,
Ashok.
Hello Ashok,
I assume that the sch. finally got to you.
Have you tried direct connection of the SAA7350? It has integrated opamps that cannot be avoided so omitting another stage can be worth if it is driving a preamp with a healthy load and able to digest the high frequency garbage.
That's the way I have it, with some 2uF caps between the DAC outputs and rca connectors (no muting
).
This thread moved me to take this player out of the shelve after two years, and I'm surprised how much I like it. Loads of detail and good bass, although with a strange tonal balance, somehow nasal. Improving supplies should help here, though.
Just for your info, SAA7350 has a bitstream output that bypasses the swith cap. filter. I can search what pins do it if someone is interested.
Cheers,
Roberto
I assume that the sch. finally got to you.
Have you tried direct connection of the SAA7350? It has integrated opamps that cannot be avoided so omitting another stage can be worth if it is driving a preamp with a healthy load and able to digest the high frequency garbage.
That's the way I have it, with some 2uF caps between the DAC outputs and rca connectors (no muting
). This thread moved me to take this player out of the shelve after two years, and I'm surprised how much I like it. Loads of detail and good bass, although with a strange tonal balance, somehow nasal. Improving supplies should help here, though.
Just for your info, SAA7350 has a bitstream output that bypasses the swith cap. filter. I can search what pins do it if someone is interested.
Cheers,
Roberto
Some small changes.
I changed the headphone chip from JRC4559D to an OPA2134. There is improvement in voice and the hf and transients. I am not so sure about the bass. But surely it was an improvement. I use a HD580 , 600 ohm headphone. For low impedance phones like 150 ohms I think the OPA2134 is OK. Lower that that you will have to check it out. I put a socket in place so that I can try other chips or defeat the phones output altogether.
The main output is through two OPA2134's. The sound was compared to a TDA1541 with tube output.
It is quite good. Bass is not the same. Transient drums do not have as much bite ( not as meaty ) as the TDA. Voice is good and Hf is good but a bit light weight ! Guitar strings seem to lack body as compared to the TDA.
I will have to try tubes and bypass the existing filters and capacitors. Mute transistors will have to go and be replaced by a relay. This Cd player is really great for tweaking ! Lots of things that one can try out.
Cheers.
The picture shows the OPA2134 in the line output stage. Note the machined sockets.
I changed the headphone chip from JRC4559D to an OPA2134. There is improvement in voice and the hf and transients. I am not so sure about the bass. But surely it was an improvement. I use a HD580 , 600 ohm headphone. For low impedance phones like 150 ohms I think the OPA2134 is OK. Lower that that you will have to check it out. I put a socket in place so that I can try other chips or defeat the phones output altogether.
The main output is through two OPA2134's. The sound was compared to a TDA1541 with tube output.
It is quite good. Bass is not the same. Transient drums do not have as much bite ( not as meaty ) as the TDA. Voice is good and Hf is good but a bit light weight ! Guitar strings seem to lack body as compared to the TDA.
I will have to try tubes and bypass the existing filters and capacitors. Mute transistors will have to go and be replaced by a relay. This Cd player is really great for tweaking ! Lots of things that one can try out.
Cheers.
The picture shows the OPA2134 in the line output stage. Note the machined sockets.
Attachments
Hi,
RR, could you also send me the schematics please?
I'm certainly the guy that Peng was talking about for the CD62, I posted some pictures of mine here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=20592&highlight=
Can you confirm that it's similar to the CD850?
Thank you
RR, could you also send me the schematics please?
I'm certainly the guy that Peng was talking about for the CD62, I posted some pictures of mine here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=20592&highlight=
Can you confirm that it's similar to the CD850?
Thank you
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.